Ceramic materials, process for producing them and objects produced from them

摘要

Materials which reflect radiation, in particular heat, are described which comprise a porous ceramic matrix having a porosity in the range from 20 to 60% by volume, the porosity/ceramic interfaces predominantly having a selected range of curvature radius of the same order of magnitude as the range of the wavelengths of a given radiation, which is to be reflected, for effective scattering of the radiation. Processes for producing such materials with sintering of the ceramic particles of wavelength size at such a temperature that they sinter without a substantial increase in particle size are described.